Show floating date indicator while scrolling in Chats

[Khizarshah01]

As an EmbeddedChat developer

I need to display a floating date indicator while scrolling through long conversations

So that users can always understand the date context of the currently visible messages, even during fast scrolling

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Context

This functionality is already present in the Rocket.Chat core web client, but is currently missing in EmbeddedChat.

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Acceptance Criteria

• A floating date indicator appears at the top of the message list while the user is scrolling
• The indicator updates dynamically when scrolling into messages from a different date
• The indicator disappears shortly after scrolling stops
• The indicator does not block message interaction (non-interactive)
• Existing inline date separators continue to work as before

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Demo

Current behavior (indicator not present):

Screencast.from.2026-01-27.00-15-28.mp4

Expected behavior (indicator present):

Screencast.from.2026-01-27.00-14-18.mp4